Method for subjecting a biomass feedstock to hydropyrolysis

Abstract

The present invention relates to a process for subjecting a biomass feedstock to hydropyrolysis, the process comprising at least the steps of: a) supplying a biomass feedstock and a fluidization gas comprising hydrogen to a bulk reactor zone of a fluidized bed reactor containing a deoxygenation catalyst; b) subjecting the biomass feedstock to a hydropyrolysis reaction in the bulk reactor zone of the fluidized bed reactor by contacting the biomass feedstock with the deoxygenation catalyst in the presence of the fluidization gas, thereby obtaining a hydropyrolysis reactor output comprising at least one non-condensable gas, a partially deoxygenated hydropyrolysis product and char; wherein the bulk reactor zone is cooled by a cooling fluid flowing through a plurality of tubes traversing the bulk reactor zone, the plurality of tubes having an inlet into the bulk reactor zone and an outlet out of the bulk reactor zone; and wherein the temperature of the cooling fluid flowing in the tubes at the point (“A”) where the biomass feedstock enters the bulk reactor zone is at least 320 °C, preferably at least 340 °C, more preferably at least 350 °C, even more preferably at least 370 °C, yet even more preferably at least 380 °C.

Description

[0001] The present invention relates to a hydropyrolysis method and a fluidized bed reactor for converting biomass feedstock into liquid hydrocarbon materials suitable for use as fuel or as a blending component in fuel.

[0002] With increasing demand for liquid transport fuels, dwindling reserves of "easily recoverable oil" (crude oil that can be easily obtained and recycled), and growing constraints on the carbon footprint of such fuels, it is becoming increasingly important to develop ways to produce liquid transport fuels from alternative sources in an efficient manner.

[0003] Biomass provides a renewable source of carbon and refers to biomaterials derived from living or dead organisms, including lignocellulosic materials (e.g., wood), aquatic materials (e.g., algae, aquatic plants, and seagrass), and animal byproducts and waste (e.g., viscera, fat, and sewage sludge). Liquid transport fuels produced from biomass are sometimes referred to as "biofuels." Therefore, using such biofuels may achieve more sustainable CO2 emissions compared to petroleum-derived fuels.

[0004] However, conventional biomass pyrolysis, typically carried out in an inert atmosphere during rapid pyrolysis, yields a dense, acidic, reactive, liquid bio-oil product. This product contains water, oil, and carbon formed during the process. Therefore, using bio-oil produced via conventional pyrolysis presents several disadvantages. These disadvantages include increased chemical reactivity, water miscibility, high oxygen content, and a low calorific value. These products are generally difficult to upgrade into alternative liquid hydrocarbon fuels.

[0005] Recently, the use of hydrogen in biomass pyrolysis (i.e., hydropyrolysis) has been disclosed. For example, hydropyrolysis methods such as those described in US 8,492,600 have been found to overcome many of the disadvantages of conventional rapid pyrolysis methods, including those mentioned above.

[0006] Hydrogenation and pyrolysis of biomass feedstocks can be carried out in reactor vessels containing fluidized beds. Fluidized beds generally consist of solid particles, such as catalysts, which are agitated and fluidized by an airflow that travels upward through the bed and exits the bed at or near the top of the reactor.

[0007] However, it is now recognized that conventional fluidized bed reactors can have various drawbacks when used for the hydropyrolysis of biomass feedstocks on a commercial scale. For example, when operating at a commercial scale, temperature control within the reactor is a primary concern due to the minimum temperature required at the reactor inlet and the maximum permissible temperature at the reactor outlet. That is, the reactor inlet temperature generally needs to be maintained above a certain minimum temperature to prevent operability issues (e.g., the formation of sticky materials) and to obtain a suitable commercial yield of the desired product, while the reactor outlet temperature needs to be maintained below a certain maximum temperature to obtain catalyst stability and a suitable yield of the desired product. However, when operating a conventional fluidized bed reactor to meet the minimum reactor inlet temperature, the heat generated by the exothermic hydrodeoxygenation reaction occurring within the reactor often causes the reactor outlet temperature to far exceed the maximum permissible temperature, unless excessive quenching gas or ballast gas is used, both of which are economically undesirable.

[0008] The purpose of this invention is to minimize one or more of the problems mentioned above or otherwise.

[0009] Another object of the present invention is to provide a method for subjecting biomass feedstock to hydropyrolysis, wherein the deposition of viscous materials such as tar in a fluidized bed reactor is minimized or even avoided.

[0010] One or more of the above or other objectives can be achieved by a method of subjecting biomass feedstock to hydropyrolysis, the method comprising at least the following steps:

[0011] a) Supplying biomass feedstock and hydrogen-containing fluidizing gas to the main reactor section of a fluidized bed reactor containing a deoxygenation catalyst;

[0012] b) By contacting the biomass feedstock with the deoxygenation catalyst in the presence of fluidizing gas, the biomass feedstock undergoes a hydropyrolysis reaction in the main reactor zone of the fluidized bed reactor, thereby obtaining a hydropyrolysis reactor output containing at least one non-condensable gas, partially deoxygenated hydropyrolysis products, and carbon.

[0013] The main reactor section is (indirectly) cooled by cooling fluid flowing through multiple pipes that pass through it. These pipes have inlets entering the main reactor section and outlets exiting it.

[0014] The temperature of the cooling fluid flowing in the pipe at the point where the biomass feedstock enters the main reactor area is at least 320°C, preferably at least 340°C, more preferably at least 350°C, even more preferably at least 370°C, and even more preferably at least 380°C.

[0015] According to the present invention, it has been surprisingly found that by utilizing the hydropyrolysis method and fluidized bed reactor disclosed herein, the deposition of viscous materials such as tar in the fluidized bed reactor can be minimized or even avoided.

[0016] In addition to cooling the bulk reactor zone, the multiple tubes running through it also help prevent the formation of large bubbles in the fluidized bed. Furthermore, these tubes help promote axial mixing of the catalyst and thus facilitate heat transfer from the top to the bottom of the bulk reactor zone.

[0017] Another advantage of this invention is that a suitable minimum temperature can be maintained at the reactor inlet while not exceeding the maximum temperature at the reactor outlet. Additionally, the method and reactor disclosed herein offer the advantage that the biomass feedstock supplied to the reactor inlet is rapidly heated and dispersed together with the catalyst present in the fluidized bed reactor.

[0018] Furthermore, the temperature of the fluidized bed can be maintained under control without the injection of any quenching fluid, thus avoiding the risks of cold spots in the fluidized bed and subsequent tar formation or reduced product yield. Because the temperature of the fluidized bed is kept under control, the risks of runaway reactions and subsequent safety-related problems are avoided. In addition, the generation of non-condensables is minimized, while the production of liquid fuels is maximized.

[0019] In step a) of the method according to the invention, a biomass feedstock and a fluidizing gas containing hydrogen are supplied to the bulk reactor zone of a fluidized bed reactor containing a deoxygenation catalyst. Typically, the bulk reactor zone is preceded by a mixing zone (discussed further below), where the biomass feedstock, deoxygenation catalyst, and fluidizing gas are mixed.

[0020] Biomass raw materials

[0021] Those skilled in the art will readily understand that there are no particular limitations on biomass feedstocks, and that they may contain any combination of biomass and / or biomass-derived feedstocks.

[0022] As used herein, the term "biomass" generally refers to material derived from organisms living on the Earth's surface or in the Earth's oceans, rivers, and / or lakes. Representative biomass may include any plant material or mixture of plant materials, such as hardwoods (e.g., whitewood), conifers, hardwood or conifer bark, pine, lignin, algae, and / or duckweed (seagrass). Energy crops or other agricultural residues (e.g., logging residues) or other types of plant waste or plant-derived waste may also be used as plant material. In addition to "dedicated" energy crops such as switchgrass, Miscanthus, and algae, specific exemplary plant materials include corn fiber, corn stalks, and bagasse. Short-rotation forest products such as energy crops include alder, ash, southern beech, birch, eucalyptus, poplar, willow, paper mulberry, Australian blackwood, sycamore, and paulownia varieties. Other examples of suitable biomass include vegetable oils, carbohydrates (e.g., sugars), organic waste such as waste paper, construction and demolition waste, and biosludge.

[0023] "Biomass-containing" feedstocks may include all or substantially all biomass, but may also contain significant amounts (e.g., at least about 5% by weight, such as about 5% by weight to about 55% by weight, or at least about 25% by weight, such as about 25% by weight to about 45% by weight) of non-biological materials (e.g., petroleum-derived materials, such as plastics, or materials derived from minerals extracted from the earth, such as metals and metal oxides, including glass). An example of a "biomass-containing" feedstock that may include one or more non-biological materials is municipal solid waste (MSW).

[0024] "Biomass-derived," as used, for example, in the phrase "biomass-derived feedstock," refers to products generated or obtained from the thermal and / or chemical conversion of biomass or biomass-containing feedstocks (e.g., MSW) as defined above. Thus, representative biomass-derived feedstocks include, but are not limited to, pyrolysis products (e.g., bio-oils), roasting products (e.g., roasted and optionally densified wood), hydrothermal carbonization products (e.g., biomass pretreated and densified by acid hydrolysis in hot, compressed water), and polymerization products (e.g., organic polymers derived from plant monomers). Other specific examples of biomass-derived products (e.g., used as feedstocks) include black liquor, pure lignin, and lignin sulfonates. Biomass-derived feedstocks also extend to feedstocks pretreated or obtained by thermal and / or chemical conversion prior to or upstream of a feedstock used in a given conversion step (e.g., hydropyrolysis). Other examples of suitable biomass feedstocks include those described in US10,822,546, the relevant disclosure of which is incorporated herein by reference.

[0025] Biomass feedstocks can be used in a dried form, for example, after undergoing a drying process sufficient to reduce the moisture content of the initial feedstock to less than about 1% by weight, or even less than about 0.1% by weight. According to other embodiments, the biomass feedstock may include moisture (e.g., a moisture content greater than about 1% by weight, such as from about 1% to about 20% by weight, preferably less than 12% by weight). In other embodiments, the biomass feedstock may be used in the form of an aqueous slurry.

[0026] The rate at which biomass feedstock is fed into a fluidized bed reactor depends in particular on temperature, amount of catalyst, and hydrogen partial pressure within the reactor.

[0027] The weight hourly space velocity (WHSV) in a fluidized bed reactor, calculated by dividing the combined weight velocity of the biomass feedstock by the weight of the catalyst stock in the reactor, is typically 0.1 hr. -1 up to 10 hours -1 Typically 0.5hr -1 up to 5 hours -1 And often 0.8hr -1 up to 3 hours -1 Generally speaking, the fluidization rate, catalyst size and bulk density, as well as the feed size and bulk density, are selected so that the deoxygenation catalyst is retained in the fluidized bed, while the generated carbon is carried out of the reactor.

[0028] The precise catalyst WHSV suitable for a given combination of feedstock and catalyst depends on the properties of the feedstock and catalyst, as well as the desired composition of the product to be obtained. The atmosphere in the reactor should consist primarily of hydrogen (but other inert gases such as CO2 may also be present), and the feedstock flow rate should not be so high that the gaseous products of feedstock decomposition dilute the hydrogen atmosphere to a level that no longer yields the hydrogen partial pressure required for the desired reaction sequence.

[0029] Deoxygenation catalyst

[0030] Those skilled in the art will readily understand that there are no particular limitations on the deoxygenation catalysts used in this invention.

[0031] The deoxygenation catalysts suitable for use herein typically comprise one or more active metals selected from cobalt, molybdenum, nickel, tungsten, ruthenium, platinum, palladium, iridium, and iron. Preferably, one or more active metals are selected from cobalt, molybdenum, nickel, and tungsten.

[0032] The metals present in deoxygenation catalysts are typically supported, preferably on a metal oxide support. Metal oxides that can be used as deoxygenation catalyst supports include alumina, silica, titanium dioxide, cerium dioxide, zirconium oxide, magnesium oxide, and binary oxides such as silica-alumina, silica-titanium dioxide, and cerium dioxide-zirconia. Preferred supports include alumina, silica, and titanium dioxide. The support may optionally contain fine particles of recycled, regenerated, and reactivated waste hydrotreating catalysts (e.g., fine particles of CoMo on an oxide support, fine particles of NiMo on an oxide support, and fine particles of NiW-containing hydrocracking catalysts on a mixture of oxide supports and zeolites).

[0033] For noble metals (e.g., ruthenium, platinum, palladium and iridium), the total metal loading on the deoxygenation catalyst is preferably in the range of 0.05% to 3% by weight, and for common metals (e.g., cobalt, molybdenum, nickel, tungsten and iron), it is in the range of 1% to 75% by weight (weight percentage is expressed as the weight percentage of the total amount of all active metals on the calcined catalyst in their reduced (metallic) form).

[0034] Additional elements such as phosphorus, boron, and nickel can be incorporated into the catalyst to improve the dispersion of the active metal.

[0035] Deoxygenation catalysts can be prepared by any suitable method known in the art. Suitable methods include, but are not limited to, co-precipitation of the active metal and the support from solution; uniform deposition of the active metal onto the support; impregnation of the support with a solution of the active metal to reduce its pore volume; continuous and repeated impregnation of the support with a solution of the active metal, wherein a drying or calcination step is performed between consecutive impregnations; and co-milling the support with a solution or powder containing the active metal. Furthermore, combinations of two or more of these methods can be used.

[0036] The deoxygenation catalyst is not limited to a specific shape and may exist, for example, in the form of spherical catalyst particles. The particle size of the catalyst used in commercial reactors in the hydropyrolysis step is preferably in the range of 0.3 mm to 4.0 mm, more preferably in the range of 0.4 mm to 2.0 mm, and most preferably in the range of 0.5 mm to 1.6 mm.

[0037] fluidized bed reactor

[0038] There are no particular limitations on the fluidized bed reactor used in this invention. Since those skilled in the art are familiar with fluidized bed reactors and their use, this reactor will not be discussed in detail herein.

[0039] The fluidized bed reactor of the present invention typically includes a mixing zone, a bulk reactor zone, and optionally includes an enlarged solids separation zone (i.e., a section having an enlarged reactor diameter or cross-sectional area relative to the diameter or cross-sectional area of ​​the bulk reactor zone) at a suitable height above the bulk reactor zone to facilitate the separation of solid carbon particles from solid catalyst particles. The fluidized bed reactor may include one or more downcomers that fluidly connect the bulk reactor zone located at or near the top of the reactor to the mixing zone located at or near the bottom of the reactor.

[0040] As used herein, the term "mixing zone" is used to describe the area located at or near the bottom of a fluidized bed reactor, in which the mixing of biomass feedstock, deoxygenation catalyst, and hydrogen-containing fluidizing gas occurs. According to this disclosure, the biomass feedstock and fluidizing gas are supplied to the mixing zone of the fluidized bed reactor via one or more inlets, preferably located at or near the bottom of the reactor.

[0041] Additionally, a catalyst recirculation stream containing the deoxygenation catalyst can be supplied to the mixing zone via one or more downcomers, which are fluidly connected to the bulk reactor zone located at or near the top of the fluidized reactor bed, such that the catalyst recirculation stream is drawn from the bulk reactor zone and supplied to the mixing zone via the one or more downcomers. Preferably, the biomass feedstock is supplied to the mixing zone at a point above the inlet of the catalyst recirculation stream (if present), such that the biomass feedstock is rapidly heated from ambient temperature to the target temperature required for hydropyrolysis. Furthermore, it is preferable to allow the catalyst recirculation stream to thermally equilibrate with the fluidizing gas before contacting the biomass feedstock to achieve the fastest possible heat transfer.

[0042] The mixing zone typically comprises one or more cylindrical containers, such as one to five. Biomass feedstock, fluidizing gas, and catalyst recirculation stream can each be introduced into one or more cylindrical containers within the mixing zone via one or more (e.g., 1 to 10) inlet locations, which may correspond to different axial heights within the mixing zone. In one embodiment, the biomass feedstock can be supplied to the mixing zone via more than one inlet location at different axial heights. Preferably, in the mixing zone, the biomass feedstock inlet is located above the catalyst recirculation stream inlet and the fluidizing gas inlet. The mixing zone typically comprises about 4% to about 30% of the total reactor volume, preferably about 10% to about 20% of the total reactor volume. While the precise dimensions of the mixing zone can vary, it typically has an inner diameter of 0.1 m to 3 m, preferably more than 0.15 m and preferably less than 2 m, more preferably less than 1 m, and even more preferably less than 0.6 m. Taking into account factors such as the number of cylindrical containers used and other operating conditions, including the apparent gas velocity of the fluidizing gas, the rate at which the biomass feedstock is introduced into the mixing zone, the amount of catalyst and the partial pressure of hydrogen within the reactor, and the desired residence time of the catalyst, biomass, and fluidizing gas in the mixing zone, determining the appropriate size of the mixing zone is within the capabilities of those skilled in the art. Similarly, determining the appropriate size of the mixing zone, considering factors such as the apparent gas velocity of the fluidizing gas, such that backmixing of biomass from the bulk reactor zone located above the mixing zone is negligible, is also within the capabilities of those skilled in the art.

[0043] Optionally, the mixing zone may also include one or more mixing devices. Suitably, any device that promotes axial and / or radial mixing within the mixing zone may be used in the fluidized bed reactor of this disclosure. An example of such a suitable mixing device includes a deflector ring positioned at the wall of the mixing zone.

[0044] In addition to the mixing zone, the fluidized bed reactor of this disclosure also includes a bulk reactor zone. As used herein, the term "bulk reactor zone" is used to describe the area in the fluidized bed reactor located downstream (i.e., above) the mixing zone, where the hydropyrolysis of biomass primarily occurs. Biomass is supplied from the mixing zone to the bulk reactor zone. In the bulk reactor zone, the biomass is contacted with a deoxygenation catalyst in the presence of a fluidizing gas under desired hydropyrolysis conditions to produce a hydropyrolysis reactor output comprising at least one non-condensable gas, partially deoxygenated hydropyrolysis products, and char. Subsequently, in a preferred embodiment of the invention, at least a portion of the deoxygenation catalyst is removed from the bulk reactor zone of the hydropyrolysis reactor via one or more downcomers to form a catalyst recirculation stream supplied to the mixing zone.

[0045] The bulk reactor zone typically occupies about 70% to about 96% of the total reactor volume, preferably about 80% to about 90%. Determining the appropriate size of the bulk reactor zone, taking into account factors such as the size of the mixing zone and other operating conditions, such as the apparent gas velocity of the fluidizing gas, the partial pressure of hydrogen within the reactor, the operating temperature, and the desired residence time of the biomass and fluidizing gas, is within the capabilities of those skilled in the art. Determining the appropriate size of the bulk reactor zone, taking into account operating conditions such as the apparent gas velocity of the fluidizing gas, such that biomass backmixing from the bulk reactor zone to the mixing zone is negligible, is also within the capabilities of those skilled in the art.

[0046] According to the present invention, the fluidized bed reactor includes a plurality of tubes extending through a main reactor zone. The tubes have inlets entering the main reactor zone and outlets exiting the main reactor zone, wherein the reactor zone can be (indirectly) cooled by cooling fluid flowing through the tubes. The cooling fluid flowing through the tubes cools the main reactor zone indirectly, i.e., the cooling fluid itself remains within the tubes and does not directly contact the contents of the main reactor zone.

[0047] Optionally, the bulk reactor zone may also include one or more internal components for heat exchange and / or one or more defoamers to prevent agglomeration. Additionally, the bulk reactor zone may optionally include one or more gaseous and / or liquid (water, hydrocarbon) quenchers for reducing the temperature within the bulk reactor zone.

[0048] As described above, the fluidized bed reactor of this disclosure may (and preferably does) include one or more downcomers that fluidly connect a bulk reactor zone located at or near the top of the reactor to a mixing zone located at or near the bottom of the reactor, so as to supply a catalyst recirculation stream from the bulk reactor zone to the mixing zone. Generally, the one or more downcomers allow the catalyst recirculation stream to flow downward from the bulk reactor zone to the mixing zone. In one embodiment, the downcomer may be an external pipe, or alternatively, the downcomer may be internally located within the core of the fluidized bed reactor.

[0049] Considering the properties of the biomass feedstock, the conditions within the reactor, and the specific fluidizing gas used, fluidization in the mixing zone and bulk reactor zone of a fluidized bed reactor can be carried out using a fluidizing gas with an apparent velocity effective for the desired type of fluidization (e.g., bubbling bed fluidization). Generally, a hydrogen-containing fluidizing gas will have an apparent velocity typically greater than about 0.1 m / s (e.g., about 0.1 m / s to about 20 m / s), greater than 0.2 m / s (e.g., about 0.2 m / s to about 1.5 m / s), typically greater than about 0.3 m / s (e.g., about 0.3 m / s to about 1.2 m / s), and often greater than about 0.5 m / s (e.g., about 0.5 m / s to about 1 m / s). A suitable fluidizing gas stream primarily contains hydrogen, but may also contain other non-condensable gases (e.g., CO, CO2, and / or CH4).

[0050] Preferably, the apparent gas velocity of the fluidizing gas in the mixing zone is equal to or higher than that in the bulk reactor zone. Generally, the higher apparent gas velocity in the mixing zone compared to a standard fluidized bed allows for the use of larger biomass particles, as they do not settle to the bottom and form sediment. Selecting a suitable combination of apparent gas velocity, mixing zone length, and mixing zone diameter, taking into account factors such as the rate of biomass feed into the mixing zone, the amount of circulating catalyst, the partial pressure of hydrogen in the reactor, and the desired residence times of the biomass, catalyst, and fluidizing gas, is within the capabilities of those skilled in the art. Determining a suitable combination of apparent gas velocity, mixing zone length, and mixing zone diameter, considering factors such as the dimensions of the mixing zone and the bulk reactor zone, such that backmixing of biomass from the bulk reactor zone located above the mixing zone is negligible, is also within the capabilities of those skilled in the art.

[0051] In step b) of the method according to the invention, the biomass feedstock is subjected to a hydropyrolysis reaction in the bulk reactor zone of the fluidized bed reactor by contacting the biomass feedstock with a deoxygenation catalyst in the presence of a fluidizing gas, thereby obtaining a hydropyrolysis reactor output containing at least one non-condensable gas, partially deoxygenated hydropyrolysis products and carbon.

[0052] The term "hydropyrolysis" is generally used to refer to a method of rapidly heating and thermally decomposing biomass feedstocks in an atmosphere primarily composed of hydrogen, in the presence of solid catalyst particles. Hydropyrolysis provides a means of removing oxygen from biomass and other feedstocks containing significant amounts of carbon and chemically bonded oxygen to produce light hydrocarbon products, wherein most of the oxygen is removed from the feedstock-derived liquid. Representative hydropyrolysis methods have been described in detail in US 8,492,600 and US 8,841,495, the relevant disclosures of which are incorporated herein by reference.

[0053] There are no particular restrictions on the conditions in the main reactor zone of a fluidized bed reactor, as long as the hydrogenation pyrolysis reaction can occur.

[0054] According to the invention, the bulk reactor zone is cooled by a cooling fluid flowing through a plurality of pipes that pass through the bulk reactor zone, the pipes having inlets entering the bulk reactor zone and outlets exiting the bulk reactor zone. Furthermore, according to the invention, the temperature of the cooling fluid flowing in the pipes at the point where the biomass feedstock enters the bulk reactor zone (typically from the mixing zone) is at least 320°C, preferably at least 340°C, more preferably at least 350°C, even more preferably at least 370°C, and even more preferably at least 380°C. Surprisingly, according to the invention, by using a plurality of pipes through which the cooling fluid flows and by using a relatively high-temperature cooling fluid, the deposition of viscous materials such as tar can be minimized or even avoided. Moreover, the deoxygenation reaction is completed at more than 75% simultaneously, and the temperature of the cooling fluid flowing in the pipes at the point where the biomass feedstock enters the bulk reactor zone is at least 320°C and preferably at most 480°C.

[0055] Those skilled in the art will readily understand that the plurality of pipes (through which the cooling fluid flows) penetrating the main reactor zone can vary in many ways. Preferably, the plurality of pipes penetrate the main reactor zone substantially parallel to each other. Moreover, it is preferable that the plurality of pipes penetrate the main reactor zone substantially vertically (so that the cooling flow flows upward or downward). The plurality of pipes may be U-shaped, such that the inlet entering the main reactor zone and the outlet leaving the main reactor zone are at the same height, for example, at the top (or bottom) of the main reactor zone.

[0056] The plurality of tubes may or may not extend into (and thus through) at least a portion of the mixing zone of the fluidized bed reactor.

[0057] Preferably, the biomass feedstock is contacted with the deoxygenation catalyst in the main reactor zone at an operating temperature ranging from 320°C to 500°C, more preferably from 350°C to 480°C, and even more preferably from 370°C to 450°C.

[0058] The precise operating temperature depends on the composition of the feedstock to be hydropyrolyzed, the characteristics of the deoxygenation catalyst, and the desired composition of the product to be obtained.

[0059] Based on a preferred embodiment of the method according to the invention, the temperature of the cooling fluid flowing in the pipe at the point where the biomass feedstock enters the main reactor zone is at least 20°C lower than the operating temperature in the main reactor zone, preferably at least 30°C lower, and more preferably at least 40°C lower.

[0060] When the plurality of pipes extend into (and thus through) at least a portion of the mixing zone, the temperature of the cooling fluid flowing through the pipes in the mixing zone is preferably at least 20°C lower than the operating temperature in the mixing zone, preferably at least 10°C lower than the operating temperature in the mixing zone, and more preferably at least 5°C lower. By keeping the temperature of the cooling fluid flowing through the pipes in the mixing zone close to, and preferably at least at, the operating temperature in the mixing zone, the temperature of the mixing zone can be closely regulated.

[0061] Of course, in order to achieve a cooling effect within the main reactor zone, the temperature of the cooling fluid flowing through the pipes in the main reactor zone is lower than the highest temperature within the main reactor zone. Preferably, the temperature of the cooling fluid flowing in the pipes at the point where the biomass feedstock enters the main reactor zone is lower than the temperature at which the hydropyrolysis reactor effluent leaves the main reactor zone (“outlet temperature”). Preferably, the temperature of the cooling fluid flowing in the pipes at the point where the biomass feedstock enters the main reactor zone is at most 480°C, preferably at most 440°C, even more preferably at most 400°C, and even more preferably at most 380°C.

[0062] According to a particularly preferred embodiment of the method according to the invention, the cooling fluid comprises a molten salt, preferably a molten metal nitrate. The advantages of using molten salts as the cooling fluid are that they typically possess high thermal conductivity, long service life, long-term chemical stability, and a boiling point safely above the maximum operating temperature of the fluidized bed.

[0063] Although there are no particular restrictions on molten salt, its melting point should be lower than the operating temperature of the bulk reactor zone.

[0064] Typically, molten salts can be alkali metal halides, alkaline earth metal halides, or nitrates. Suitable examples of molten salts are salts selected from lithium fluoride, sodium fluoride, potassium fluoride, beryllium fluoride, rubidium fluoride, boron fluoride, zirconium fluoride, potassium chloride, sodium chloride, potassium nitrate, sodium nitrate, lithium nitrate, potassium carbonate, sodium carbonate, lithium carbonate, or mixtures thereof. Molten salts / metals exist in reaction zones at temperatures above their melting points.

[0065] There are no particular restrictions on the pressure within the bulk reactor zone. Preferably, the biomass feedstock is contacted with the deoxygenation catalyst in the bulk reactor zone at a pressure ranging from 0.50 MPa to 7.50 MPa.

[0066] The precise operating pressure of a fluidized bed reactor depends on the composition of the feedstock to be hydropyrolyzed, the choice of catalyst, the composition of the fluidizing gas (i.e., the purity of the hydrogen-rich gas), and the desired composition of the product to be obtained.

[0067] The temperature of the fluidizing gas is typically in the range of 100°C to 800°C, preferably 200°C to 600°C, and more preferably 300°C to 500°C.

[0068] Optionally, the fluidized bed reactor of this disclosure may further include an enlarged solids separation zone (i.e., a section with an enlarged reactor diameter or cross-sectional area relative to the diameter or cross-sectional area of ​​the main reactor zone) at a suitable height above the main reactor zone to facilitate the separation of solid carbon particles from solid catalyst particles. The enlarged separation zone may have a reduced apparent gas velocity to facilitate the effective separation of relatively small diameter catalyst particles that would otherwise be swept away by the main reactor zone at a higher apparent gas velocity. Other gas-solid separation devices (e.g., filters, cyclone separators, etc.) may be used instead of the enlarged solids separation zone, but are preferably used in combination with it.

[0069] Preferably, the method according to the invention further includes the following steps before step a):

[0070] i) The biomass feedstock, fluidizing gas, and catalyst recirculation stream containing deoxygenation catalyst are supplied to the mixing zone of the fluidized bed reactor;

[0071] ii) Allowing biomass feedstock, fluidizing gas, and deoxygenation catalyst to move upwards from the mixing zone to the bulk reactor zone through the fluidized bed reactor; and

[0072] iii) At least a portion of the deoxygenation catalyst is removed from the bulk reactor zone to form a catalyst recirculation stream, which is supplied to the mixing zone in step i).

[0073] More specifically, the fluidized bed reactor of this disclosure uses one or more downcomers to supply a hot catalyst recirculation stream from the bulk reactor zone located at or near the top of the reactor to the mixing zone located at or near the bottom of the reactor. In this manner, the hot catalyst can be removed from the bulk reactor zone located at or near the top of the reactor and transferred to the mixing zone located at or near the bottom of the reactor, thereby achieving more efficient axial heat transfer throughout the reactor and thus maintaining it within the inherent temperature range of the process chemistry. Furthermore, by introducing the catalyst recirculation stream and biomass feedstock into the mixing zone located at or near the bottom of the reactor, the biomass feedstock can be rapidly heated upon contact with the hot catalyst recirculation stream and more fully dispersed in the deoxygenation catalyst, thus benefiting the hydropyrolysis method.

[0074] The hydropyrolysis method disclosed herein produces a hydropyrolysis reactor output comprising partially deoxygenated hydropyrolysis products (e.g., in the form of condensable vapors), at least one non-condensable gas (e.g., CO, CO2, and / or CH4), and carbon particles. As used herein, “partially deoxygenated hydropyrolysis products” may include oxidized hydrocarbons (e.g., derived from cellulose, hemicellulose, and / or lignin) which may undergo more complete deoxygenation in subsequent (downstream) hydroconversion processes (e.g., to produce hydrocarbons and remove oxygen in the form of CO, CO2, and / or water). The representative oxygen content of the partially deoxygenated hydropyrolysis products is generally in the range of about 1% by weight to about 30% by weight, or about 5% by weight to about 25% by weight.

[0075] According to a preferred embodiment of the method based on the present invention, the method further includes the following steps:

[0076] c) Remove substantially all carbon from the hydropyrolysis reactor output to provide a purified hydropyrolysis reactor vapor stream;

[0077] d) Hydroconversion of at least a portion of purified hydropyrolysis reactor vapor stream in at least one hydroconversion reactor containing a hydroconversion catalyst to produce hydroconversion reactor output; and

[0078] e) Recover essentially completely deoxygenated hydrocarbon liquid and gas mixtures from the output of the hydroconversion reactor.

[0079] Carbon removal

[0080] More specifically, following hydropyrolysis, representative methods may also include removing all or substantially all of the carbon particles and / or other solid particles (e.g., fine catalyst particles) from the hydropyrolysis reactor effluent to provide a purified hydropyrolysis reactor vapor stream with reduced carbon content. Carbon particle removal can be particularly important as the hydropyrolysis products (including the purified hydropyrolysis product vapor stream or a portion thereof) undergo a fixed-bed catalytic conversion process. In this case, the removal of fine carbon particles prevents problems associated with premature clogging of the fixed bed when carbon particles are trapped within the voids of the fixed catalyst bed. As defined herein, removing substantially all carbon particles means that at least 99% by weight of the carbon particles in the hydropyrolysis reactor effluent are excluded from the purified hydropyrolysis product vapor stream. According to another embodiment, 99.9% by weight or at least 99.99% by weight of the carbon particles are excluded.

[0081] Methods for removing carbon and catalyst particles are generally not limited and may include any method suitable for use with the hydropyrolysis method of this disclosure. A suitable method for removing carbon and catalyst particles from the vapor stream is by cyclone separation. Other examples of suitable carbon removal include those described in US10,822,546, the relevant disclosure of which is incorporated herein by reference.

[0082] Hydrogenation Conversion Reactor

[0083] In another embodiment, the method of this disclosure may optionally further include the hydroconversion of at least a portion of the partially deoxygenated hydropyrolysis product or purified hydropyrolysis reactor vapor stream in a hydroconversion reactor vessel comprising a hydroconversion catalyst (e.g., as a fixed bed). Hydroconversion reactor output is produced, from which a substantially completely deoxygenated hydrocarbon liquid and gas mixture can be recovered. Suitable hydroconversion catalyst compositions comprise catalysts suitable for hydrodeoxygenation and aromatic saturation. This step can be suitably carried out at a temperature in the range of 150°C to 400°C and a pressure in the range of 0.50 MPa to 7.50 MPa. The weight hourly space velocity (WHSV) of this step is approximately 0.1 h⁻¹. -1 approximately 2 hours -1 Within the range.

[0084] Conditions in hydroconversion reactors typically range from 200°C to 475°C, typically from 260°C to 450°C, and often from 315°C to 430°C. The weight hourly space velocity (WHSV) of a hydroconversion reactor, calculated by dividing the total weight flow rate of the feed to the reactor (e.g., the purified vapor stream obtained from the hydropyrolysis reactor after carbon particle removal) by the weight of the catalyst stock in the reactor, is typically 0.01 hr. -1 up to 5 hours -1 Typically 0.05hr -1 up to 5 hours -1 And often 0.1hr -1 up to 4 hours -1 .

[0085] In another aspect, the present invention provides a fluidized bed reactor suitable for performing a method according to the invention for subjecting biomass feedstock to hydropyrolysis, the reactor comprising at least:

[0086] - A bulk reactor zone containing a deoxygenation catalyst, configured to produce a hydropyrolysis reactor output comprising at least one non-condensable gas, partially deoxygenated hydropyrolysis products, and carbon; and

[0087] - Multiple pipes penetrate the main reactor zone, each pipe having an inlet for entering the main reactor zone and an outlet for exiting the main reactor zone, wherein the main reactor zone can be cooled by cooling fluid flowing through the pipes; and

[0088] The reactor is configured such that the temperature of the cooling fluid flowing in the tube at the point where the biomass feedstock enters the main reactor zone is at least 320°C, preferably at least 340°C, more preferably at least 350°C, even more preferably at least 370°C, and even more preferably at least 380°C.

[0089] As described above, preferably, the cooling fluid contains a molten salt, preferably a molten metal nitrate.

[0090] Based on a preferred embodiment of the fluidized bed reactor according to the invention, the reactor further includes a mixing zone, one or more downcomers fluidly connecting the mixing zone and the main reactor zone, and an outlet located at the top of the fluidized bed reactor, the outlet being configured to produce hydropyrolysis reactor output.

[0091] The mixing zone includes: one or more inlets fluidly connected to a biomass feedstock source; one or more inlets fluidly connected to a fluidizing gas source; and one or more inlets at one or more outlets of one or more downcomers for fluidly connecting the mixing zone and the bulk reactor zone; and

[0092] The bulk reactor zone is positioned above the mixing zone.

[0093] The invention will be further described below with reference to the following non-limiting drawings. Wherein:

[0094] Figure 1 A first embodiment of a reactor suitable for carrying out the method according to the invention is schematically shown;

[0095] Figure 2 schematically shown Figure 1 A top view of the mixing zone shown;

[0096] Figure 3 A second embodiment of a reactor suitable for carrying out the method according to the invention is schematically shown; and

[0097] Figure 4 schematically shown Figure 3 A top view of the mixed zone shown.

[0098] For descriptive purposes, the same reference numerals denote the same or similar parts.

[0099] Figure 1The fluidized bed reactor (generally indicated by reference numeral 100) includes a mixing zone 110, a bulk reactor zone 150, and an enlarged solids separation zone 160. The mixing zone 110 includes a cylindrical container 105. Biomass feedstock 120 is supplied to the cylindrical container 105 in the mixing zone 110 of the reactor 100 via one or more inlets.

[0100] Although not in Figure 1 As depicted, the biomass feedstock 120 can be supplied to the cylindrical container 105 via more than one inlet location, which can be at different axial heights. A fluidizing gas stream 130 is supplied to the fluidized bed reactor 100 via one or more inlets at or near the bottom of the reactor 100 and can be used to entrain any solid particles present in the biomass feedstock 120. Figure 1 In one embodiment, the catalyst recirculation stream 140 is taken from reactor 100 via one or more outlets in the main reactor zone 150 and supplied to the mixing zone 110 of the hydropyrolysis reactor 100 via one or more inlets. In the mixing zone 110, the biomass feedstock, fluidizing gas, and deoxygenation catalyst (in...) Figure 1 In one embodiment, it is mixed (at least in part supplied by catalyst recirculation stream 140) and subsequently supplied to bulk reactor zone 150.

[0101] In the main reactor zone 150, the biomass feedstock undergoes hydropyrolysis in the presence of a deoxygenation catalyst to produce a hydropyrolysis reactor output comprising at least one non-condensable gas, partially deoxygenated hydropyrolysis products, and carbon. This output is discharged as hydropyrolysis reactor output stream 170 via one or more outlets.

[0102] The bulk reactor zone 150 includes a plurality of parallel, vertically extending pipes 155 that penetrate the decomposition zone 160 and a portion of the bulk reactor zone 150 (and the mixing zone 110). The plurality of pipes 155 have inlets 156 entering the bulk reactor zone 150 and outlets 157 exiting the bulk reactor zone. Figure 1 In one embodiment, the plurality of pipes are U-shaped, such that the inlet 156 entering the main reactor zone 150 and the outlet 157 exiting the main reactor zone are located at the top of the main reactor zone 150. The main reactor zone 150 can be cooled by a cooling fluid flowing through the pipes 155. Preferably, the cooling fluid is molten salt.

[0103] During use, the temperature of the cooling fluid flowing in pipe 155 at point A, where the biomass feedstock enters the main reactor zone 150 from the mixing zone 110, is at least 320°C.

[0104] Figure 2 It shows Figure 1Top view of the mixed zone 105 in the image.

[0105] Figure 3 and Figure 4 Alternative embodiments of reactors suitable for carrying out the method according to the invention are schematically illustrated. From Figure 4 As can be seen more clearly in the top view, this alternative implementation includes four separate mixing zones.

[0106] discuss

[0107] As can be seen from the above examples, the method and fluidized bed reactor according to the present invention allow for an efficient way to subject biomass feedstocks to hydropyrolysis while avoiding the deposition of sticky materials such as tar.

[0108] Those skilled in the art will readily understand that many modifications can be made without departing from the scope of the invention.

Claims

1. A method for subjecting biomass feedstock to hydropyrolysis, the method comprising at least the following steps: a) Supplying biomass feedstock and hydrogen-containing fluidizing gas to the main reactor section of a fluidized bed reactor containing a deoxygenation catalyst; b) By contacting the biomass feedstock with the deoxygenation catalyst in the presence of the fluidizing gas, the biomass feedstock is subjected to a hydropyrolysis reaction in the main reactor zone of the fluidized bed reactor, thereby obtaining a hydropyrolysis reactor output containing at least one non-condensable gas, partially deoxygenated hydropyrolysis products, and carbon. The main reactor zone is cooled by cooling fluid flowing through a plurality of pipes that pass through the main reactor zone, the plurality of pipes having an inlet for entering the main reactor zone and an outlet for leaving the main reactor zone; The temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the main reactor zone is lower than the temperature at which the hydropyrolysis reactor output leaves the main reactor zone and is at least 320°C; wherein the main reactor zone is positioned above the mixing zone, and wherein the plurality of tubes extend into at least a portion of the mixing zone.

2. The method according to claim 1, wherein the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at least 340°C.

3. The method according to claim 1, wherein the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at least 350°C.

4. The method according to claim 1, wherein the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at least 370°C.

5. The method according to claim 1, wherein the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at least 380°C.

6. The method according to claim 1, wherein the biomass feedstock is contacted with the deoxygenation catalyst in the bulk reactor zone at an operating temperature in the range of 320°C to 500°C.

7. The method according to claim 1, wherein the biomass feedstock is contacted with the deoxygenation catalyst in the bulk reactor zone at an operating temperature in the range of 350°C to 480°C.

8. The method according to any one of claims 1-7, wherein the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the main reactor zone is at least 20°C lower than the operating temperature in the main reactor zone.

9. The method according to any one of claims 1-7, wherein the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the main reactor zone is at least 30°C lower than the operating temperature in the main reactor zone.

10. The method according to any one of claims 1-7, wherein the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at least 40°C lower than the operating temperature in the bulk reactor zone.

11. The method according to any one of claims 1-7, wherein the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at most 480°C.

12. The method according to any one of claims 1-7, wherein the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at most 440°C.

13. The method according to any one of claims 1-7, wherein the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at most 400°C.

14. The method according to any one of claims 1-7, wherein the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at most 380°C.

15. The method according to any one of claims 1-7, wherein the cooling fluid comprises molten salt.

16. The method according to any one of claims 1-7, wherein the cooling fluid comprises molten metal nitrate.

17. The method according to any one of claims 1-7, wherein the biomass feedstock is contacted with the deoxygenation catalyst in the bulk reactor zone at a pressure ranging from 0.50 MPa to 7.50 MPa.

18. The method according to any one of claims 1-7, wherein the method further comprises the following step before step a): i) The biomass feedstock, the fluidizing gas, and the catalyst recirculation stream containing the deoxygenation catalyst are supplied to the mixing zone of the fluidized bed reactor; ii) Allowing the biomass feedstock, the fluidizing gas, and the deoxygenation catalyst to move upward from the mixing zone to the bulk reactor zone through the fluidized bed reactor; as well as iii) At least a portion of the deoxygenation catalyst is removed from the bulk reactor zone to form the catalyst recirculation stream, which is supplied to the mixing zone in step i).

19. The method according to any one of claims 1-7, wherein the method further comprises the following step: c) Remove at least 99% by weight of carbon from the output of the hydropyrolysis reactor to provide a purified hydropyrolysis reactor vapor stream; d) Hydroconversion of at least a portion of the purified hydropyrolysis reactor vapor stream in a hydroconversion reactor containing a hydroconversion catalyst to produce a hydroconversion reactor output; and e) Recover a fully deoxygenated mixture of hydrocarbon liquids and gases from the output of the hydroconversion reactor.

20. A fluidized bed reactor suitable for performing the method of hydropyrolysis of biomass feedstock according to any one of claims 1-19, said reactor comprising at least: - A bulk reactor zone containing a deoxygenation catalyst, the bulk reactor zone being configured to produce a hydropyrolysis reactor output comprising at least one non-condensable gas, partially deoxygenated hydropyrolysis products, and carbon; and - A plurality of pipes extending through the main reactor zone, the pipes having inlets entering the main reactor zone and outlets exiting the main reactor zone, wherein the main reactor zone can be cooled by cooling fluid flowing through the pipes; and The reactor is configured such that the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the main reactor zone is at least 320°C. as well as A mixing zone, wherein the bulk reactor zone is positioned above the mixing zone, and wherein the plurality of tubes extend into at least a portion of the mixing zone.

21. The reactor of claim 20, wherein the reactor is configured such that the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at least 340°C.

22. The reactor of claim 20, wherein the reactor is configured such that the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at least 350°C.

23. The reactor of claim 20, wherein the reactor is configured such that the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at least 370°C.

24. The reactor of claim 20, wherein the reactor is configured such that the temperature of the cooling fluid flowing in the tube at the point ("A") where the biomass feedstock enters the bulk reactor zone is at least 380°C.

25. The reactor of claim 20, wherein the cooling fluid comprises molten salt.

26. The reactor of claim 20, wherein the cooling fluid comprises molten metal nitrate.

27. The reactor according to any one of claims 20-26, the reactor further comprising one or more downcomers fluidly connecting the mixing zone and the bulk reactor zone and an outlet located at the top of the fluidized bed reactor, the outlet being configured to produce the hydropyrolysis reactor output; The mixing zone includes: one or more inlets fluidly connected to a biomass feedstock source; one or more inlets fluidly connected to a fluidizing gas source; and one or more inlets for fluidly connecting the mixing zone and the main reactor zone to one or more outlets of the one or more downcomers.

Images